Understand what the interviewer is asking for by using test cases and questions about the problem.

• Q
  • What is the desired outcome?
    • To calculate the total time to visit all required observation points in a given order.
  • What input is provided?
    • A string station_layout representing the layout of observation points, and a string observations representing the order of required observations.

Plan the solution with appropriate visualizations and pseudocode.

General Idea: Map each letter in station_layout to its index, then calculate the total time to move from one observation point to another based on observations.

1) Create a dictionary `layout_index` to map each letter in `station_layout` to its index. 2) Initialize `current_index` to 0 and `total_time` to 0. 3) Iterate through `observations`: - For each character, find its index in `station_layout`. - Calculate the time to move to the new index and add it to `total_time`. - Update `current_index` to the new index. 4) Return `total_time`.

⚠️ Common Mistakes

• Not correctly mapping each letter to its index in the layout.

def navigate_research_station(station_layout, observations): # Create a dictionary to map each letter to its index in the station layout layout_index = {} for idx, char in enumerate(station_layout): layout_index[char] = idx # Initialize the starting index (initially at 0) current_index = 0 total_time = 0 # Iterate through each character in the observations string for char in observations: # Find the index of the current character in the station layout target_index = layout_index[char] # Calculate the time taken to move to the target index total_time += abs(current_index - target_index) # Update the current index to the target index current_index = target_index return total_time